Claims
- 1. A driver for rotating a magnetic playback head affixed thereto comprising
- (a) a housing,
- (b) an armature rotatably mounted within said housing,
- (c) at least two field magnets affixed at spaced intervals within said housing and positioned around the axis of rotation for said armature,
- (d) a driving coil affixed in said housing concentric with at least a portion of said armature whereby a current passing through said coil develops a continuously variable magnetic field polarizing said armature and causing a continuously variable preferential attraction of said armature toward an adjacent one of said field magnets and a corresponding continuously variable repulsion of said armature from an adjacent other of said field magnets, thereby tending to rotate said armature a direction and distance continuously proportional to the magnitude and polarity of said current, and
- (e) means for concentrating the magnetic flux from said field magnets so as to return said armature to a home position when no current is applied to said coil.
- 2. A driver as claimed in claim 1 wherein said means for concentrating the magnetic flux comprises
- a pair of peaked projections on said field magnets each disposed at radially opposing positions within said housing and projecting inwardly from said housing, and
- a pair of peaked projections on said armature also disposed at radially opposing positions symmetric about the axis of rotation for said armature.
- 3. A driver as claimed in claim 1 wherein said armature includes a central bore and a hollow shaft inserted in said bore.
Parent Case Info
This is a division of application Ser. No. 211,265 filed Nov. 28, 1980, now U.S. Pat. No. 4,433,351.
US Referenced Citations (12)
Foreign Referenced Citations (4)
Number |
Date |
Country |
1294522 |
Mar 1969 |
DEX |
925603 |
May 1963 |
GBX |
980144 |
Jan 1965 |
GBX |
2022874A |
Dec 1979 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Patent Abstracts of Japan, vol. 2, No. 124, Oct. 18, 1978, p. 7291E78. |
Divisions (1)
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Number |
Date |
Country |
Parent |
211265 |
Nov 1980 |
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